This relates generally to displays for computer-based devices.
Conventionally, a computer may paint an image on a display. An image may be rendered and then painted on a display by painting pixels with the appropriate colors to produce the rendered image. The image location within the frame is determined by its coordinates. The image may be created from a member of overlying image layers, each layer being successively painted on the display.
However, in some cases, a computer system may have additional displays which are coupled over a universal serial bus link. Specifically, a universal serial bus to digital visual interface link allows a number of additional displays to be controlled. These displays, called external or extended displays, may operate in a clone mode wherein they display the same information that is displayed on the main display or they may operate in an extended display mode in which they display information different from what is displayed on the main display.